Teach ConnectivityManager about UID-specific rules derived from policy,
such as rejecting network traffic on "paid" interfaces. Calls that
return NetworkInfo now filter based on any REJECT rules in effect for
the calling UID. (Added uid parameter if callers that still want all
interfaces.)
Changed NetworkPolicyManager to derive rules based on current policy
combined with PowerManager and ActivityManager status, which it passes
to ConnectivityService for eventual enforcement through netd. When
rules change the usability of a NetworkInfo for a specific UID, it also
dispatches CONNECTIVITY_ACTION broadcasts to that UID. Combined paid
and background policy together to match current working definition.
Change-Id: I797ea49439fcc487cfe2cbc16703d4b91ceb9af6